This is it:
"The Barclay and Perkins of Vienna, Herr Dreher, died suddenly a few days ago. He was the best producer of Vienna beer, and died worth from 6,000,000fl. to 8,000,000fl. (£800,000). His heir is his only son, a boy of 14. The boy, after finishing school, is to come for three years to England, to Barclay and Perkins's establishment, work there till the age of 21, and then assume the patrimony."
Lincolnshire Chronicle - Friday 15 January 1864, page 7.
When you think about it, it isn't so strange. Dreher's Schwechat brewery was the largest on the continent and Barclay Perkins had for a while been the largest brewery in the world. Though you might have expected the young Dreher to do his apprenticeship in a Lager brewery.
I wonder if Anton Dreher had set uit up remembering his own highly-significant rtip to Britain in the 1830's. The trip that gave birth to the first industrial bottom-fermenting styles styles: Munich and Vienna Lagers.